Abstract: Disclosed is a process for producing stably a polyarylene sulfide of high purity and high molecular weight by contacting a dihalogeno aromatic compound with an alkali metal sulfide in a polar solvent which comprises, as a first stage, reacting a dihalogeno aromatic compound with an alkali metal sulfide in a polar solvent in the presence of a lithium compound and in the presence of substantially no water at 200.degree.-270.degree. C. with concentration of remaining alkali metal sulfide being 5.5 g/l-polar solvent or less in terms of sulfur; then adding water in an amount of 1.0-10 mols per 1 mol of said alkali metal sulfide; and, thereafter, as a second stage, carrying out the reaction at 220.degree.-280.degree. C. Preferred dihalogeno aromatic compound is p-dichlorobenzene, preferred alkali metal sulfide is sodium sulfide and/or lithium sulfide and preferred lithium compound is lithium chloride and/or lithium sulfide.

Abstract: Disclosed is a method for producing a polyarylene sulfide comprising contacting a dihalogenated aromatic compound with an alkali metal sulfide in a polar solvent, wherein a halogenated aromatic compound containing active hydrogen is present in the reaction system.

Abstract: A process for the production of polyesterpolycarbonate is described, which comprises reacting an aqueous alkaline solution of dihydric phenol and an organic solvent solution of acid chloride to prepare polyester oligomer, mixing chloroformate group-containing polycarbonate oligomer with the polyester oligomer, and polycondensing the polyester oligomer and the polycarbonate oligomer to form the polyesterpolycarbonate.

Abstract: A flame retardant polycarbonate resin composition comprising a polycarbonate resin, a nuclear substituted benzoic acid containing at least one substituent selected from the group consisting of thiosalicylic acid and dihydroxy benzoic acid, and tetrabromobisphenol A or ##STR1## .